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11o Drawing.

Be itlmown that l' CARn S Ueinsmoii citizen of the United tates,lresidin at l etroit, in the county QfWa ne and lists of 'Michi an, have invented-a: newweindfllmf-f' proved Process of Recoveringifioiistituents My invention relates-to" thetreatment of alkaline deposits such asf the brine ot Seal-lee Lake in California, which contains sodium chlorid, sodiun'i' sulfate isodiunicarbonate, sodium "tetroboratef and potassium chlorid, and the object of my. improve ments is to provide an economical and -e{fi cicnt method of recovering the "potassium; chlorid and other con-tentsof value of such brines in a commercially-pure Stated 1 As is :well known a! considerable proporj tion of the sodium sulfate content of/such: brines can be removed by chillingfithe brine to a. temperature of 'zero centigrade such chillin' however does not' eau sei precipitw:

tion' 0 the sodiurn'carbonate'or borax and-- the presence of these is is source 'of diiiiculty'inf the final vacuumpan' evaporat1on inprocesses directed to, the recovery-o l? the potassium chlorid, theformer by formm a 1 scale onthe heating pipes whereby t e.

transmission ot-heat is lminimized and thelatter by containinatin'g the I crystall zed- .potassium chlorid product. c The objectof my improvements 1s to ob.

viate these diliiculties and my invention is; based-upon the fact, Wl'llGlLI have dlSQQV-L 'ered, that if the brine be chilled in the first,

instance to a point materially below zero centigrade, not only is a more com lete precipitation of the sodium sulfate e ected but 7 l chlond can'be evaporated forfl'further crops of potassium chlori d at least twice before also the sodium carbonate and boraxyare thrown down to such an extent that the are not present in sufficient quantit in the ate'r v} stages of the process 'to inter em w th ts pure state whichhas notvhe'retofore been possible and anappreciableincrease in oon- 1n%. 1 1 t v v V he'saltstvhich'are removed at'-'14 0., from the chilled brine will contain or centJ ofthe-original carbonateas N 0,,- 10171- 0, togetherwithlargeamounts of hy- In carrying my mvehtion into effect I.

first chill the brine to a low temperature,

Vany appreciableextent;I odiun chloridis thrown outat,a'highaternperature".and can be recovered ca es cent." ure which is not G3,:thpiigh 'lg clo not -limitmy invenjtionkto I the'use of this exact temperature. ,By such, chilling about two. thirds ,of the I bore-x and 1 temperatures prevail as? in the 1 vicinity of Seatls; Lakejzand therefore .artificial refrigoration must iorcl-inarily' be. resorted to. This is moreove-r preferable not only be ,csuse of itsgr'eater intensityI-zbut becauseit; a can be regulated and controlled w-and r-is not subjectto'the-variability of thefiveather: l c

3 "'Ifhe; chillLingmay-fbe efiectedin cone b'ot-fl torn tanks containing :1 cooling coilsinsideof v ivl1ic1 1;liqui'd anlnioniafis evaporating- 1The;

precipitated? salts settle to'sthe bottomof the cone and are drawn ofi' and'separate'd in the fro ng'the liquor by :inean's of a 3 filter wheel r other suitable device. The clear liquorsis thenf ifydesired; evaporated. in l solar ponds until just saturated with potas- 'siumch'lorid-{wh n the eli'uor isrjdrawh oflv from-"theprecipitatled rso ium ichloridkand; 'otherfpsalts. 11'Ihe...liquor vis then evaporated at a high temperature preferably L111 inul- E tiplefeflectevaporators until saturated withpotassiurn' chlorid at the high-temperature. v v Thehotli 'uor is then drawn off fromthe u precipitate a salts and is cooledto crystallize -v out potassium chlorid; Because of the-refl movalof bore? in thefirs't instance no tom precipitates out at this point asis usually the case:

The mother liquor jfibmzthe' potassium boraxjbegrnst, -.gcontaminate the-cropsto-i a t v ip 'r n During the case when'sodium car nate is notrenioved "from" the ravwbrine by extreme chill In order to recover the sodium carbonate content the mixed, salts are allowed to warm up to about125' C.,,which' causes them to partially melt.

Theliquor contains upward (of- 100 ra-ms per liter, M 00, while the solid saf maining are nearly pure sodium sulfate. The carbonate-containing liquor is filtered from th'e'solid'salts at about 25 (1., and is then blown with carbon dioxid-icontaining %as, such askiln gas, whereb sodium bicarona-terisprecipitated whic 1 may then be washed; filtered'ancbcalcined to yield'soda I'donot claimherei-nrthe above described method of recovering sodium bicarbonate, but have made the: same the subject of a separate application: for Letters Patent; filed .April -3,1920, Serial No. 370,966.

Having thus described my invention what;

I'claimas .new and desire to secure by Let+ ters Patent is,-.

1. The process of recovering potassium chlorid from solutions in which it is con tainedltogetherrwith sodiumrchlorid, sodium sulfate, sodium carbonate. and .borax, whichconsists-in .chilling the solution soas to :pre-

cipitate sodium sulfate, sodium carbonate and borax; and:- separating out the precipitated: sa-lts, evaporating the cleared brine first by. solar-heat: until it isapproxlmately saturated with potassium chlorid :and then, after sgi aratioiri from precipitated salts; by, heat at a. high-temperature and artifici without: admixture of? other-ssalts, untilit is saturatedc with otassium chlorid= at the temperature em oyed andlfinally separate ing the brine rom the salts precipitated during' tiieihigh' temperature evaporation and cooling in to crystallize: out potassium chlorid:

2: The process; of recovering; potassium chlorid 'from solutions in which it is contained together, with sodiumchlorid, sodium sulfate, sodium carb'onatevandifb'orax, which consists in chilling the solution to approximatelyl.49 C.,,so. as to-precipitate sodium sulfate, sodium carbonate and borax and concentrate the solution by the removal of the Water of crystallization inthese salts and'separating out the precipitated salts, evaporating.- the: cleared brine first L by, solar heat until it is approximately, saturated with potassium ohilorid'and :then, aftersepa: ration from precipitated: salts, .by artificial heat at a; high-temperature o andiwithout; admixture of: other salts,-;.until it is saturated with potassiiunclilerid at thentemperature employed," and finally separatingthe brine from the salts'precipitatedj during the high temperature evaporation, and cooling; it to crystallize out; potassium chlorid.

3. Telie process of" recovering potassiiun chlorid fIOl'l'h'SOllllllUIlSilIl which it is con-- tained=v to ether; w-ithsodiunichlorid, sodium sulfate, sodium carbonate and borax, whiclrconsists in chilling; the solutioni to approximately. --14 0., soias to precipitate sodium sulfate, sodium: carbonate and 2 borax; and concentratethe solution by the removal of;-1th-ewaterrof crystallization in these salts, andseparating out the; recipitatecl salts,,evaporating theclearec brine,

withoutadmiztu-re of o ther:v salts, at a,- high temperaturemntil it is saturated with potas In testimony whereof. I have affixed my:

signature-this 18th day of-September, 1918.

s CLALRLv SUNDSTROM; 

